Congress Member Votes MCP server

@pipeworx/congress-member-votes

How each U.S. House member voted, how often they were there, and how often they vote with their party, from the U.S. House Clerk's roll-call votes.

Part of Pipeworx — an MCP gateway connecting AI agents to 1875+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

• membervotepositions(bioguideid | name [+ state], bill?, questioncontains?, fromroll?, toroll?, limit?, congress?, session?) — one member's position (Yea, Nay, Present, Not Voting, or not on the roll) on roll calls, newest first. Answers "how did Rep. X vote on bill Y".
• memberattendancepartyline(bioguideid | name [+ state], fromroll?, toroll?, congress?, session?) — attendance and party-line share for one member over a session or roll range. Every figure carries its denominator and exclusions; a figure that cannot be computed is null with a stated reason, never 0% or 100%.
• rollcallpositions(roll_number, party?, state?, position?, congress?, session?) — every member's position on one roll call, with party tallies.

What the derived figures mean

• Attendance denominator: recorded roll calls in the range on which the member was on the roll. Quorum calls and Speaker elections are excluded (and counted in excluded_rolls). attended = Yea + Nay + Present; missed = Not Voting.
• Not on the roll is not Not Voting. A member absent from a roll entirely (not yet seated, or already gone) is excluded from the denominator and counted separately as notonroll_excluded.
• withpartymajority: of the member's Yea/Nay votes, the share matching what a strict majority of their own party's Yea/Nay voters did. Includes lopsided votes, so it runs high. Party-tied rolls are excluded and counted.
• partyunity**: the same, restricted to rolls where a majority of Democrats opposed a majority of Republicans.
• The Speaker is listed on a roll only when voting, so a Speaker's missed-vote count cannot be derived; attendance is returned as null with that reason (party-line is still computed over the votes cast).
• Party is the member's party at their latest roll call. Independents have no D-versus-R majority, so no party-line figure is computed for them.

Auth

Keyless.

Coverage

House only. 119th Congress, sessions 1 and 2. Other Congresses and the Senate return a named reason. Senate roll-call records could not be read: the Secretary of the Senate's site refused every request (HTTP 403) from this service and from a separate machine on 2026-10-23.

Data sources

• U.S. House Clerk, roll-call votes. US federal data, public domain.

Rolls are held as a compact member-by-roll table, generated by scripts/bake-congress-member-votes.mjs (the refresh path), uploaded at deploy and injected into the pack (pack-baked-indexes.json). Rolls newer than the table are read from the Clerk live on each call (up to 40), so every response states the last roll it covers (rollscovered), how many were added live (livetopup) and dataasof. If the live read fails the response says so and covers only the stored rolls.

The Clerk answers a roll that does not exist with an HTTP 200 stub rather than a 404; the pack treats that as "no such roll" and any other non-record body as a fault.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "congress-member-votes": {
      "url": "https://gateway.pipeworx.io/congress-member-votes/mcp"
    }
  }
}

What this endpoint actually serves

Shortened. The full README is on GitHub.